1. Field of the Invention
The present invention relates to focusing (control method) in an image pickup apparatus, such as a digital camera and a digital video camera.
2. Description of the Related Art
Autofocusing based on the sharpness (AF evaluation value) of an image obtained by processing an output signal from an image pickup device in an image pickup apparatus is known, and will be described as “TV-AF” hereinafter. In this TV-AF, the wobbling is used to find an in-focus direction and then mountain climbing is performed in the in-focus direction. In the wobbling, the focus lens is micro-reciprocated in the optical-axis direction at a predetermined period and the center of the reciprocation of the focus lens is moved in a direction in which the AF evaluation value increases (Japanese Patent Laid-Open No. 2005-121819).
However, along with the recent miniaturization of the image pickup device, when a motor having a limited stopping resolution, such as a stepping motor, is used for wobbling, a movement of the focus lens problematically appears on an image.